1. Technical Field
The present disclosure relates generally to telecommunications and more particularly to a wireless telecommunications system.
2. Description of the Related Art
FIG. 1 depicts a schematic diagram of a portion of a typical wireless telecommunications system designated generally as 10. System 10 serves a number of wireless terminals 22 and 24 that are situated within a geographic area. System 10 includes wireless switching center 12 that is connected to a number of base stations 14i and local and long distance telephone networks 16. Wireless switching center 12 routes or “switches” calls from and to wireless terminals or, alternatively, between a wireless terminal and a wireline terminal connected to wireless system 10, via local and/or long distance telephone networks 16.
The geographic area serviced by wireless system 10 is partitioned into a number of spatially distinct areas called cells. As depicted in FIG. 1, each cell 20i is schematically represented by a hexagon. In practice, however, each cell 20i usually has an irregular shape that depends, for example, on the topography of the terrain serviced by system 10. Typically, each cell 20i contains a corresponding base station 14i. Base station 14i includes antennas and radios to communicate with wireless terminals 22 and 24. Each base station 14i also includes transmission equipment to communicate with wireless switching center 12.
In designing system 10, engineers allocate a limited number of frequency channels to each base station 14i using well known techniques. Base stations 14i communicate with wireless terminals over these frequency channels. Thus, the number of base stations limits the potential capacity of system 10 for processing calls to and from wireless terminals.
As wireless telecommunications have increased in popularity, designers have developed techniques for increasing the capacity of these wireless telecommunications systems. One common technique is to reduce the size of each cell by “splitting” existing cells into multiple cells. Some designers have even suggested reducing the size of cells to provide so called “microcells” that service very small geographic regions.
The public has resisted use of microcells for several reasons. First, many people fear that electromagnetic radiation from base stations could cause health problems. Further, real estate in populated areas is typically expensive and accounts for about half the cost of the base station. Thus, it is a difficult and expensive proposition to split cells to increase capacity of a wireless telecommunications system.